Personal opinion is that it's Draymond, not the on-ball defender, who bothers Tatum so much. That's why it didn't matter much that Wiggins was out tonight. Draymond's help defense is almost flawless, and he nearly always cuts off Tatum's first option as soon as he makes his move.
Same way Tatum "shut down" Durant in the first round last season. He definitely did his job spearheading the defense, not taking anything away from him, but to shake up an elite player it takes more than the first guy. For us that might mean Smart, Al, Rob when he's healthy. For GS it's mostly Draymond.